In recent years, wireless networks have emerged as flexible and cost-effective alternatives to conventional wired local area networks (LANs). At the office and in the home, people are gravitating toward use of laptops and handheld devices that they can carry with them while they do their jobs or move from the living room to the bedroom. This has led industry manufacturers to view wireless technologies as an attractive alternative to Ethernet-type LANs for home and office consumer electronics devices, such as laptop computers, Digital Versatile Disk (“DVD”) players, television sets, and other media devices. Furthermore, because wireless networks obviate the need for physical wires, they can be installed relatively easily.
Wireless communication systems adapted for use in homes and office buildings typically include an access point coupled to an interactive data network (e.g., Internet) through a high-speed connection, such as a digital subscriber line (DSL) or cable modem. The access point is usually configured to have sufficient signal strength to transmit data to and receive data from remote terminals or client devices located throughout the building. For example, a portable computer in a house may include a PCMCIA card with a wireless transceiver that allows it to receive and transmit data via the access point. Data exchanged between wireless client devices and access points is generally sent in packet format. Data packets may carry information such as source address, destination address, synchronization bits, data, error correcting codes, etc.
A variety of wireless communication protocols for transmitting packets of information between wireless devices and access points have been adopted throughout the world. For example, in the United States, IEEE specification 802.11 and the Bluetooth wireless protocol have been widely used for industrial applications. IEEE specification 802.11, and Industrial, Scientific, and Medical (ISM) band networking protocols typically operate in the 2.4 GHz or 5 GHz frequency bands. In Europe, a standard known as HIPERLAN is widely used. The Wireless Asynchronous Transfer Mode (WATM) standard is another protocol under development. This latter standard defines the format of a transmission frame, within which control and data transfer functions can take place. The format and length of transmission frames may be fixed or dynamically variable
In a manner similar to the wireless router described above, fixed wireless systems involve systems that are capable of enabling wireless communication, however fixed wireless systems also generally connect to the interactive data network through a broadband wireless connection. Fixed wireless systems are referred to as “fixed” because they are typically situated in fixed locations. Unlike the mobile devices, such as portable telephones and personal digital assistants that can be configured to connect to a wireless router, fixed wireless devices can be much larger in size, less mobile, and can include devices such as desktop personal computers.
Although having an enormous amount of potential, fixed wireless communication has traditionally lagged wired systems in both usefulness and popularity. A primary contributing factor for this phenomenon has been the fact that data transmission in wired systems has far exceeded data transmission in wireless systems. In the past, data transmission rates for fixed wireless systems have lagged Integrated Services Digital Network (ISDN) transmission rates or even dial-up transmission rates across conventional telephone lines.
However, the obstacles to using fixed wireless systems are rapidly being overcome. With the advent of Third Generation Wireless (3G) technologies, Universal Mobile Telecommunications System (UMTS)/Wideband Code Division Multiple Access (WCDMA) technologies in Europe, and Evolution Data Only (1xEVDO) technologies in North America, fixed wireless has become a viable option for wireless broadband access in the home as part of the overall operator's 3G portfolio. Already, fixed wireless systems are capable of downlink throughput access rates in the hundreds of kilobits per second, and megabit rates will be widely available in the near future. As a result of these advances fixed wireless access through UMTS, High Speed Packet Data Access (HSDPA) or 1xEVDO is rapidly becoming a superior choice to ISDN or dial-up systems. In fact, some or all of these systems will equal or surpass the transmission rates of digital subscriber line (DSL) systems in the not-too-distant future.
As fixed wireless systems continue to increase in quality and performance, improved “gateway” products become increasingly important. Wireless gateway products are needed to permit fixed wireless devices such as personal computers, peripheral devices and other devices within a local area network (LAN) to access and communicate with larger, wide area networks (WANs). As transmission rates continue to increase, wireless gateway devices must be able to manage more and more wireless-capable devices while maintaining high transmission rates among the devices and the larger networks.
Both wireless routers and fixed wireless gateways as well as the mobile devices which connect to the router or gateway need to be configured before a mobile device can connect to the interactive data network through the router or gateway. This configuration can include setting certain identification and security information, such as a service set identifier and security key, on the router or gateway and each mobile device
A service set identifier (SSID) is a sequence of characters that uniquely names a wireless local area network (WLAN). This name allows mobile devices to connect to the desired network through the router or gateway when multiple independent networks operate in the same physical area. Each set of wireless devices communicating directly with each other is called a basic service set (BSS). Several BSSs can be joined together to form one logical WLAN segment, referred to as an extended service set (ESS). A Service Set Identifer (SSID) is typically a 1-32 byte alphanumeric name given to each ESS.
For example, a departmental WLAN (ESS) may consist of several access points (APs), such as routers or gateways, and dozens of mobile devices, all using the same SSID. Another organization in the same building may operate its own departmental WLAN, composed of APs and mobile devices using a different SSID. One purpose of SSID is to help stations in department A find and connect to APs in department A, ignoring APs belonging to department B.
A WLAN can also be configured with security features to protect against casual eavesdropping. Wired Equivalent Privacy (WEP) and WiFi Protected Access-Pre-Shared Key (WPA-PSK) are sample methods for securing an IEEE 802.11 WLAN. WEP refers to the intent to provide a privacy service to WLAN users similar to that provided by the physical security inherent in a wired LAN. When WEP is active in a WLAN, each packet of information is encrypted separately with an RC4 cipher stream generated by a 64-bit RC4 key. RC4 is a symmetric algorithm because it uses the same key for the encryption and decryption of data. This key is composed of a 24-bit initialization vector (IV) and a 40 bit WEP key. The encrypted packet can be generated with a bitwise exclusive OR (XOR) of the original packet and the RC4 stream. The IV can be chosen by the sender and can be changed periodically so every packet won't be encrypted with the same cipher stream. The IV can be sent in the clear with each packet. An additional 4-byte Integrity Check Value (ICV) can be computed based on the original packet and appended to the end. The ICV can also be encrypted with the RC4 cipher stream.
Wi-Fi Protected Access (WPA and WPA2) is a class of systems to secure (Wi-Fi) computer networks that was created in response to several perceived weaknesses in previous security systems such as WEP. In the “pre-shared key” (PSK) mode of WPA, every user in a WLAN is given the same key or passcode. Similar to WEP, data is encrypted using the RC4 steam cipher, usually with a 128-bit key and a 48-bit initialization vector. The passcode used by WPA in PSK mode may be from 8 to 63 ASCII characters or 64 hexadecimal digits (256 bits).
Both WEP and WPA-PSK require the operator of a network to set a key or passphrase on the Access Points (APs) of the WLAN and match the same key on each client station connected to the AP. Access points (such as routers and gateways) and client stations (mobile devices) must be programmed with the same key. Experts highly recommend that the key be sufficiently long and random and be changed frequently to impede hackers from cracking the key and gaining unauthorized access to the WLAN. One problem associated with wireless gateways and routers is that set up can sometimes be difficult or confusing to the owner. This can be especially true if the user wishes to set up enhanced security such as WEP or WPA-PSK on the network. Generating a key that is sufficiently long and random is not necessarily straight-forward. Configuring every node on the network with the SSID and key can be a tedious and difficult process. Setup usually involves configuring the router or gateway settings and then configuring each mobile device the user wishes to communicate through the router or gateway with the same settings as configured on the router or gateway. Repeating this procedure frequently can become very cumbersome.